The present invention is generally related to golf clubs. In particular, the present invention is related to a device to determine and adjust the loft angle and lie angle of a golf club.
Technological innovations and a greater understanding of golf swing dynamics have allowed golf club manufacturers to provide a significant level of customization to match golf clubs to a particular golfer according to the golfer""s height and preferred stance. Various golf club design parameters may be customized, such as an adjustment of the angular relationship of the golf club head with respect to the shaft and the ground. Such a customization is useful, for example, because when two golfers with id dissimilar heights address a golf ball using the same club, the angle formed by the shaft of the club with respect to the ground will invariably be different for each golfer. Similarly, depending on the golfer""s stance and playing characteristics, the angle formed by the club face of the golf club will also vary among golfers. Thus, to improve a golfer""s performance with a particular club, these are two parameters of the club regarding the relative position of the golf club head to the shaft that are often customized to fit the golfer.
Referring now to FIG. 1, a pair of lines 20, 22 represent the plane of the ground. The first example stated above concerns the golf club""s lie angle, which is defined as the angle, xcex1, formed between a center line 24 extending through the shaft with the ground line 20 as shown tangent to the sole at the centerline of the club face. To accurately obtained the lie angle xcex1 of the golf club, the sole of the club head should be resting at the point just below the center of the club face. Proper lie angle is important to ensure that the golf club makes a square contact with the ball during the execution of a swing. For example, if the lie is less than ideal, the sole of the golf club will most likely be upwardly angled when the club head impacts the ball. As a result, the face of the club head will be aimed to the left of the medial line of the fairway, resulting in a left-of-center flight path. On the other hand, if the lie is greater than ideal, the club""s sole will likely be downwardly angled at the point of impact and the opposite effect will be obtained.
The other parameter of the golf club head relative to the shaft is the loft angle, shown as xcex2 in FIG. 1. The loft angle xcex2 is generally defined as the angle of the backward slant of the face of a golf club head. More particularly, the loft angle xcex2 is the angle formed by a line 26 perpendicular to the club face to the ground line 22. The greater the loft angle, the greater the loft of ball after being struck by the golf club.
The measurements of the loft angle, for example, may not be indicative of the performance of the club when used by a particular golfer because the physiological and swing characteristics of the golfer can effect the resultant flight of the ball. Accordingly, in providing a more customized set of clubs for a particular golfer, the loft angle is often personalized to meet the particular physical traits and abilities of the individual golfer.
Moreover, as golfers rely on a golf club having a particular loft and lie angle to perform in a particular fashion, any variation based on use or manufacturing tolerance may be quite undesirable, especially for golfers playing at the professional level. Thus, minor adjustments to the loft and lie are often made to the golf clubs used by professional golfers. Such adjustments are typically required at tournaments, on tour, or at various locations remote from manufacturers. Accordingly, there is a need for a golf club adjustment device that is compact and transportable, while easy to use.
In addition, due to the mass production of golf clubs, fine tuning of each golf club by adjusting the loft and lie of the club is often desirable before the clubs are ready for shipment. Thus, manufacturers often make final adjusts to the loft and lie of the clubs after assembly of the club. Such an operation is highly labor intensive and there is a need for a device that permits adjustments to be made quickly and simply.
Finally, technological innovations have allowed manufacturers to produce golf clubs having various configurations that are designed to meet different performance criteria. Thus, there is a need for a device for measuring and adjusting the loft and lie of a golf club should be configured and adaptable to receive and securely hold golf clubs having varied club head configurations.
The present invention is directed to a device for measuring alignment of a golf club with a shaft and a head having a strike face and a back face. The golf club may be a putter. The device includes a base member and an abutment member fixed to the base member for abutting the strike face. The device further includes at least one clamping member for abutting the back face, with the at least one clamping member being disposed on the base member and spaced from the abutment member to fix the golf club head in a first direction between the at least one clamping member and the abutment member. The device also includes an alignment member coupled to the base member and spaced from the at least one clamping member in generally opposing relation thereto, with the alignment member being movable with respect to the clamping member to receive the golf club shaft in a second direction. The positioning of the alignment member simultaneously indicates the loft angle and lie angle of the golf club.
In one embodiment, the alignment member is slidably and pivotably mounted, and includes a first indicator for indicating lie and a second indicator for indicating loft. The indicator includes a fixed scale and a movable needle, with the needle being coupled to a cradle for receiving said shaft. The second indicator comprises a movable scale and a fixed needle. The base member may further include at least two leveling bearings for abutting a sole of the head. The alignment member is slidable in a direction generally transverse to the clamping member and pivotable in a direction generally parallel to the clamping member. In addition, the alignment member is slidable in a direction generally parallel to the clamping member.
An adjusting bar may also be provided and includes two protrusions, with the protrusions defining a slot therebetween to receive and contour the shaft. According to one aspect of the invention, each of the protrusions is a wheel rotatably secured to the adjusting bar and having a diameter greater than about 0.1 inches, but less than about 0.25 inches. In one embodiment, the diameter is about xe2x85x9c inch, while the slot is between about 1 to 4 inches, and can be about 2.5 inches.
The present invention is also directed to a fixture for retaining a golf club with a shaft and a head having a strike face. The fixture includes a base plate having a top surface, a reference surface fixed to the base plate, and a clamp assembly coupled to the base plate in spaced relation and generally perpendicular to the reference surface. A carriage is coupled to the base, and a measurement member is disposed in a plane generally perpendicular to the top surface. The measurement member is coupled to the carriage in spaced and opposing relation to the clamp assembly, with the measurement member including a cradle that is rotatably coupled to the measurement member and movable with respect to the clamp assembly to receive the golf club shaft. Retention of the club between the reference surface and the clamp assembly with the strike face abutting the reference surface permits the measurement member to simultaneously indicate a loft angle and a lie angle of the golf club. The measurement member is pivotably coupled to the carriage in a plane generally perpendicular to the top surface, while the carriage is movable in a direction generally transverse to the clamp assembly and in a direction generally parallel to the clamp assembly.